The Kent MP and energy minister Greg Clark says the Prime Minister showed grace under pressure during her conference speech - that was marred by a protester and a persistent cough.

He also defended plans to place an energy cap on fuel prices, saying loyal customers who stayed with companies were not getting the best deal.

The leader’s speech was beset by problems, the most notable being the interruption of a protest by the alternative comedian Lee Nelson, who handed the PM a fake P45.

He said: “It is a concern that someone could get so close to the Prime Minister and it was an unexpected distraction, but she dealt with it with grace.”

The Conservative leader used her speech to shoulder the blame for the election, and received several ovations from the audience.

Mr Clark said: “Clearly she was struggling but it was a very personal and that [the cough] made it more so. We have all had these coughs and to keep going and that was respected by people in the hall.”

He denied the plan for a cap on energy prices was an initiative that Labour had put forward.

“It is different because what Labour proposed was a freeze on energy and not a cap.

“Many people have been loyal to companies and stayed with them for years but have not been repaid for that loyalty.

“People have been loyal to suppliers who they think are reputable, particularly some of the big operators but often the truth is that have continued to suffer from very high prices.”

Mrs May said the government was in favour of free markets but “we will always taken action to fix them when they are broken”.

"The energy market punishes loyalty with higher prices, and the most loyal customers are often those with lower incomes, the elderly, people with lower qualifications and people who rent their homes,"

It is estimated that the new energy cap will save hard-pressed consumers an estimated £100 a year.